package org.example.java.util.concurrency.advanced_object;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

/**
 * Created by Juntao.Zhang on 2014/10/7.
 */
public class CountDownLatchDemo {
  final static SimpleDateFormat sdf = new SimpleDateFormat("mm:ss");

  public static void main(String[] args) throws InterruptedException {
    System.out.println("begin at " + sdf.format(new Date()));
    CountDownLatch latch = new CountDownLatch(2);//两个工人的协作
    Worker worker1 = new Worker("zhang san", 5000, latch);
    Worker worker2 = new Worker("li si", 4000, latch);
    worker1.start();
    worker2.start();
    System.out.printf("latch before is %s.%n", latch);
    latch.await(10, TimeUnit.SECONDS);//等待所有工人完成工作
//    latch.countDown();
    System.out.printf("latch after is %s.%n", latch);
    System.out.println("finish");
    System.out.println("all work done at " + sdf.format(new Date()));
  }


  static class Worker extends Thread {
    String workerName;
    int workTime;
    CountDownLatch latch;

    public Worker(String workerName, int workTime, CountDownLatch latch) {
      this.workerName = workerName;
      this.workTime = workTime;
      this.latch = latch;
    }

    public void run() {
      System.out.println("Worker " + workerName + " do work begin at " + sdf.format(new Date()));
      doWork();//工作了
      System.out.println("Worker " + workerName + " do work complete at " + sdf.format(new Date()));
      latch.countDown();//工人完成工作，计数器减一

    }

    private void doWork() {
      try {
        Thread.sleep(workTime);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }
  }


}
